Sulfonic acid surface active agent and method of preparation



Patented Apr. 10,. 1951 E. T S

SULFONIC ACID SURFACE ACTIVE AGENT AND METHOD OF PREPARATION Glen W. Hedrick, Glen Ellyn, Ill., assignor to E. F. Houghton and Company,

Philadelphia,

Pa., a corporation of Pennsylvania 11 Claims. 1

The present invention relates to novel surface active agents and more particularly it relates to surface active agents having marked detergent properties, as well as other desirable properties, comprising a new typev of chemical substance, namely the water soluble salts of a benzoyl sulpho propionic acid ester as more fully described hereinafter. This application is a continuation-inpart of application Serial No. 626,438, filed November 2, 1945, and now abandoned.

The principal object of the invention is to provide surface active agents having outstanding detergent properties, which agents ma be used wherever such properties are desired, for example, in processing textile fibres and fabrics, leather, paper, and other fibrous materials, in cleaning processes, such as general household cleaning, material cleaning, dishwashing, and the like, and in frothing, mulsifying, emulsion breaking, flotation, and other processes.

Another object is to provide compounds having detergent properties which may be used to advantage in neutral, alkaline, or acid media, either alone or in combination with other detergent materials.

Other objects, including the provision of a novel method of producing the surface active agents of the invention, will be apparent from a consideration of the specification and the claims.

Asindicated above, the surface active agents of the present invention, possessing detergent properties, comprise the water soluble salts of the benzoyl sulpho propionic acid esters, the benzoyl radical being defined as a radical of the type RCOwhere R is a phenyl or substituted phenyl radical of the type hereinafter set forth.

The surface active agents of the present invention are represented by theformula:

Where R1 is selected from the group consisting of hydrogen and alkyl groups containing from 1 to 6 carbon atoms; where R1 is selected from the group consisting of hydrogen and a methyl group; where A is selected from the group consisting of hydrogen and chlorine when R1 is as stated and R'1 is hydrogen, otherwise A is hydrogen, in other words, A is selected from the group consisting of hydrogen and chlorine except where Ri is methyl in which case A is hydrogen; where B is an ethylene group; where R2 is an alkyl group containing from 10m 16 carbon atoms; where M is a cation providing water solubility to the product; and where the total number of carbon atoms of R2 plus carbon atoms in substituted alkyl groups (R1 and/or R'1) on the phenyl nucleus is at least 10 but not more than 16.

Thus, in the above formula, the group A R I X L. 'l

may be written as X-which represents a phenyl derivative selected from the group consisting of phenyl, monochlorophenyl, monoalkyl phenyl, monochlo-romonoalkyl phenyl, and monoalkyltolyl, wherein no one of the alkyl groups contains more than 6 carbon atoms, and where the number of carbon atoms sup-plied by substituted alkyl groups attached to the phenyl nucleus provide, with the carbon atoms supplied by R2, a total of at least 10 but not more than 16 carbon atoms.

In the above formula, no attempt has been made. to indicate to which of the two carbon atoms in the ethylene (B) group the sulpho group (-SOs-M) is attached. The most practical chemical processes, however, for introducing the sulpho group into this ethylene linkage are believed to produce mixtures rather than pure alpha or pure beta derivatives. Generally, while the alpha derivative is believed to predominate, the location of the sulpho group is immaterial since it must exert a similar hydrophilic action on the molecule either in the alpha or the beta position, and it is to be understood that both the alpha and beta compounds, and mixtures thereof, are within the scope of the invention.

As pointed out in connection with the formula, M is a cation rendering the compound watersoluble, for example an alkali metal such as sodium or potassium, the ammonium radical, and the like.

The products of the present invention thus embody not only a benzoyl or chlorbenzoyl group but also a definite number of exterior or external carbon atoms in the various R groups. As stated, these external carbon atoms must total at least 10 and not more than 16.. Some or all of these external carbon atoms may be provided by an alkyl ester group, R2. Some of these external carbon atoms may be provided by a substituted alkyl group or alkyl group plus a methyl group attached to the phenyl nucleus, and as indicated, the substituted alkyl group contains no more than 6 carbon atoms. 'It is immaterial from the standpoint of the present invention whether any of the various R groups is a straight or a branched chain alkyl group. A chlorine atom may also be attached to the phenyl nucleus When R'l is hydrogen, without altering the properties of the compound significantly. Since no one alkyl group attached to the phenyl nucleus contains more than 6 carbon atoms, and since R2 must contain at least 10 but not more than 16 carbon atoms, and since the total number of external carbon atoms ranges from 10 to 16, for each ester group (R2) employed, there is a definite range of carbon atoms that may be present in the groups attached to the phenyl nucleus and vice versa. For example, if there are no groups containing carbon atoms attached to the'phenyl nucleus (i. e.

22" R; is phenyl or monochlorophenyl) the alkyl ester groups are restricted to the decyl throughcetyl groups while if, for example, an amyl group and a methyl group are attached to the phenyl nucleus (i. e.

A B1 I R is amyl tolyl) the estergroup is restricted to the decyl group.

While the numerous specific compounds may be prepared by the methods hereinafter described corresponding to the formula given for the compounds of .the invention, they will possessmarked detergent, properties, making them available for useas surface active agents in the various industrial fields.

detergent properties to the highest degree are those corresponding to the formula:

where Y is selected from the group containing hydrogen, chlorine and methyl, where R2 is an alkyl group containing from to 14 carbon atoms, and where B and M are as stated. Preferably R2 contains 12 carbon atoms and M-is sodium.

The products ofthe invention may be readily and economically prepared by condensing the desired phenyl derivative reactive in a Friedel- Crafts acylation type of reaction, with theanhydride of a four carbon atom dicarboxylic aliphatic acid, i.'e. maleic anhydride or succinic anhydride; esterifying the resulting acid; and then converting the ester into the sulpho derivative, as will be further discussed hereinafter. Another, but not preferred, method of preparing the products of the present invention is by condensing a half ester-half acid chloride of the four carbon atom dibasic acid with the phenyl derivative to provide the ester, and then converting the ester into the sulpho derivative.

In preparing the benzoyl derivative, the desired phenyl derivative furnishing not only the phenyl or monochlorophenyl nucleus, but also any substituted alkyl group or alkyl and methyl groups, is reacted by a Friedel-Crafts acylation reaction with a molar equivalent of the anhydride. The phenyl derivative may be obtained from any source, for instance from coal tar, petroleum or from synthetic processes. For example, in the case of alkylated phenyl derivatives, these may be obtained by condensing benzene with an alkyl halide or with an aliphatic olefin by a preliminary Friedel-Crafts alkylation reaction.

Examples of the phenyl derivatives that may be .used in the preparation of the benzoyl derivatives in accordance with the present invention are: benzene; monochlorobenzene; the monoalkyl benzenes such as toluene, ethyl benzene, isopropyl benzene (cumene), secondary butyl benzene, n-butyl benzene, the amyl benzenes, and the like; the monoalkyl toluenes such as Xylene, methyl isopropyl benzene (pcymene), secondary butyl toluene, the amyl toluenes, and the like; the. monoalkyl monochlorobenzenes such as chlorotoluene, ethylchlorobenzene, chlorocumene, secondary butyl chlorobenzene, and the like.

The anhydride of the fourcarbon atom .dicarboxylic aliphatic acid may be the unsaturated maleic anhydride or the saturated succinic anhydride. When maleic anhydride is employed, the benzoyl compound prior to sulphonation is a benzoyl acrylic. acid ester. Upon sulphite addition, the double bond is saturated and the product is a water soluble salt of a benzoyl sulpho propionic acid ester, wherein the SOsM group has become attached to one of the carbon atoms of the CH:CH group, and a hydrogen atom to the other. In the case of succinic anhydride, the benzoyl derivative of propionic acid is formed as a result of the Friedel-Crafts reaction, and a hydrogen atom attached either to the alpha orbeta carbon atom must be substituted by .the sulpho group as hereinafter described.

The reaction between the phenyl derivative and the anhydride to form the corresponding benzoyl acrylic or propionic acid is brought about, as has been stated above, by a Friedel-Crafts acylation reaction and any of the variousexpedients used in that type of reaction may be employed in the production of the benzoyl compound. Advantageously, the condensation is brought about by condensing the phenyl derivativewith approximately a molar equivalent of the anhydride in a suitable solvent with anhydrous or substantially anhydrous aluminum chloride. While the solvent employed may be an excess of the phenyl derivative in the case of relatively low boiling phenyl derivatives, the use of a suitable inert solvent such as carbon disulphide, orthodichlorobenzene, methylene chloride, ethylene chloride, and tetrachloroethane is preferred.

The phenyl derivative and the anhydride may be mixed with the solvent and the aluminum chloride added thereto, preferably graduall over a period of time, or the phenyl derivative may be mixed With a portion or all of the aluminum chloride and the anhydride and solvent may then be added, preferably gradually, followed by the addition of further amounts of aluminum chloride, if required. Other procedures for bringing together the phenyl derivative, the anhydride, the solvent, and the aluminum chloride may of course be used, if desired. For example, the aluminum chloride, anhydride and solvent may be mixed and the phenyl derivative gradually added thereto. The reaction, at least at the start, is exothermic and hydrogen chloride is evolved as the reaction proceeds. The reacting mixture is generally maintained at a temperature in the range from about 20 C. to about 65 C. by cooling at the start and by heatin subsequently if necessary, and it is advantageous to agitate the mixture during the reaction.

When the condensation is completed, which may be determined by cessation of the evolution of the hydrogen chloride, the 'mass may be poured into ice, water, and a small amount of mineral acid, keeping the mass cold as is the usual practice in the type of reaction, and the mixture may be agitated until the aluminum chloride complex is decomposed. The condensation product which is in solution in the solvent may then be separated from the aqueous phase and washed with water and mineral acid to remove the salts of aluminum.

The benzoyl acrylic or propionic acid may be isolated by either extracting it from the solvent with a warm 5% soda ash solution or by removing the solvent by distillation. The acid may be purified by dissolving it in a solution of a suitable alkali, such as soda ash, filtering to remove any insoluble material and precipitating the acid by the addition of mineral acid. I

In one procedure, the phenyl derivative is dissolved in an inert solvent and about onemolecular equivalent of maleic anhydride is added to the solution. The mixture is heated to a temperature at which the aluminum chloride complex remains dispersed, for example, to about 40 C., and is maintained between that temperature and about 50 C. during the reaction. The aluminum chloride (about 2 molecular equivalents) is added gradually, for example, in portions during the reaction, and the mass is agitated during the reaction. When the reaction is complete, which may require several hours-for example six hoursthe aluminum chloride complex is decomposed and the acid isolated as above described.

In a more preferred procedure, the aluminum chloride, anhydride and a chlorinated solvent are mixed and the mixture is agitated and becomes uniform. The phenyl derivative is gradually added at a temperature between about 40 C. and about 50 C., and after the addition is completed the mixture is stirred for a short period at a temperature between about 40 C. and about 60 C. The aluminum chloride complex is decomposed and the acid isolated as above described.

The benozyl acrylic or propionic acid is esterified with a compound providing the desired R2 group, and the resulting ester then converted to the sulpho derivative. The alkyl ester of the acid may be prepared by any of the suitable esterifying reactions.

In one type of method, the ester is formed by reacting the acid with one molecular equivalent of the alpihatic alcohol corresponding to the alkyl ester desired in the presence of a solvent and an esterifying catalyst such as concentrated sulphuric acid, benzeneor toluene-sulphonic acid. Preferably the solvent is one which like toluene, boils slightly above the boiling point of water. The mixture of the benzoyl acrylic or propionic acid, the alcohol, the solvent, and the esterification catalyst are boiled and the water formed by the esterification reaction is removed. After the .esterification reaction has been completed, the

ester, which is in solution in the solvent, may bewashed with water, followedin some cases by dilute alkali toremove anyunc'o'nvert'ed acid and the traces of catalyst. The ester may be isolated by removing the solvent by steam distillation, distillation at atmospheric pressure or by evaporation in vacuo.

The benzoyl acrylic or propionic acid ester may be converted into the sulpho derivative by any process by which the -SO3M group may be attached to one of the carbon atoms of the vinylene or ethylene chain of the acrylic or propionic ester.

suflicient to convert the ester into the sodium or other salt of the sulphonic acid, the use of a slight excess of the bisulphite oftenbeing advantageous. The mixture is advantageously heated in a closed container equipped with an agitator until the ester becomes completely soluble in water. The temperature of heating will depend on the particular ester being treated and usually a temperature between about C. and C. will be employed, and in many instances it willbe desirable to heat'the mixture to boiling. The ester is rendered completely soluble in water by this treatment and the product formed is the-sulphonic acid salt of the cation of the bisulphite. Thus, as stated in connection with the formula, M may be any cation which provides watersolubility, for example, an alkali metal ion, ammonium radical or the like.

Referring to the saturated benzoyl propionic acid ester, it may be first converted into 'a halogenated derivative, for example, a bromo compound, prior to sulphonation. In such conversion process, the ester is advantageouslydissolved in a solvent and small amount of a halogenating catalyst such as phosphorus trichloride-is added. The halogen, for example, bromine, is then brought into contact with the solution, for instance, by adding liquid brcmine drop-by-drop to the solution. Hydrogen halide is liberated and the reaction is completed in a short time. The

halogenated derivative is isolated by evaporation of the solvent. The halogenatedderivative thus prepared may then be sulphonated by reacting the halogen derivative with a sulphite, for example, sodium or potassium sulphite, to replace the halogen atom of the compound with the S O'3M group. Advantageously, the reaction is brought about by refluxing an aqueous mixture of the reactants until the reaction has progressed to completion. As in the case of the products obtained by the previously described method of sulphonation, the sulphonated product may be provided with the desired cation represented by M.

In order to illustrate the invention further, the following specific examples are given for the preparation of the compounds of the present invention. Two diiferent procedures were employed in preparing the compounds of the examples, which are illustrated below as Methods A and B, respectively. Each of the numerical examples, from 1 to 14, inclusive, was made according to one of these two methods and to avoid repetition of thedetails of. the procedures, each of these examples is designated as to which method was followed. In each case, a measure of the compounds surface activity isgiven by showing wetting speeds at various concentrations in water *determined by the timerequired to wet out a :gram skein of raw cotton yarn at 100 F. according to the standard Draves method.

METHOD A .The preparation of the lauryl ester of benzoyl sulpho .propionic acid, sodium salt iToa cooled and stirred mixture of 49 g. /2

I mol) maleic anhydridc, 39 g. mol) benzene and 300 cc. o-dichloro-benzene, there are added gradually in small portions 140 g. aluminum chloride. The temperature is allowed to rise slowly to .50 C.60 C. where it is maintained until no more hydrogen chloride is .given off. The material is decomposed by pouring it over 1 kg. of

crushed ice to which 100 cc. of concentrated sulphuric acid had been added. .The mixture is .stirred until the aluminum chloride complex has 'been broken up completely. Then the lower layer isidrawn off and the solvent is steam-distilled off. from the upper layer. The steam distillation residue is taken up in a mixture of 200 cc. of toluene and 93 g. of lauryl alcohol and any lower layer which may be formed is drawn off. The solution is then refluxed with cc. of concentrated sul- .phuric acid through a constant water separator until-practicallyall of the acid is esterified which requires about 4 hours. The bottom'layer is then drawn off and any mineral acid present in the oil is neutralized. The toluene is steam-distilled ofi.

The ester is then sulphonated as described under Method B. The product gave a wetting speed of 32 seconds at a concentration of .05% and was a good soft water detergent.

METHOD B 'The preparation of the lauryl ester of chlorbenzoyl sulpho propz'omic acid, sodium salt To a mixture of 49 g. mol) maleic anhydride and 105g. aluminum chloride, there are added 90 cc. of'ethylene chloride. The suspension is agi tated and water cooled. After mostof the solids have dissolved, 56 g. /2 mol) chlorbenzene are added slowly. After the addition, the mixture is stirred for minutes at C. The material is then cooled and decomposed with a mixture of 500 g. crushed ice,'10O cc. 66% sulphuric acid, :and 93 g. of lauryl alcohol. stirred for minutes at room temperature. 'lower layer is then drawn off.

The mixture is 1 cc. of concentrated sulphuric acid is added to the organic layer which is then refluxed through a constant water separator for 2 hours or longer until practically all of the acid has been esterified. The solvent is distilled off until the temperature within the oil has reached 110 C. A solution of 52 g. sodium bisulphite and 1 g. sodium hydroxide in 110 cc. of water is added to the oil. The agitated mixture is heated to C. and is maintained there for 15 minutes, after which time sulphonation is -pared,.but aspreviously set forth, other-water The to form the sulpho derivative.

condensing hexylbenzene soluble salts such as the potassium or the am- -monium salts, may be prepared by analogous procedures.

EXAMPLE 1 The salt of the n-decyl ester of benzoyl sulpho propionic acid was prepared following Method Bby first condensingbenzene with maleic anhydride. The benzoyl acrylic acid thus formed was esterified with n-dec'yl alcohol, and theresulting ester was treated with sodium bisulphite At a concentration of 2%, the compound gave a wetting speed of only '7 seconds and possessed detergent properties, .particularly in hard water.

EIQAMPLE 2 The salt of the n-decyl ester of chlorobenzoyl sulpho propionic acid was prepared following Method B by first condensing chlorobenzene with maleic anhydride. The chlorobenzoyl acrylic acid thus formed was esterifiedwith n-decyl alcohol, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. At a concentration of .1%, the compound gave a wetting speed of 40 seconds and possessed detergent and foaming properties.

EXAMPLE 3 The salt of the cetyl ester of benzoyl sulpho propionic acid was prepared following Method B by first condensing benzene with maleic anhydride. The-benzoyl acrylic acid thus formed was esterified with cetyl alcohol, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. The product gave a wetting speed of 323 seconds at a concentration of 3%.

EXAMPLE 4 The salt of the beta-butylhexyl ester of toluoyl sulpho propionic acid was prepared following Method B by first condensing toluene with maleic anhydride. The toluoyl acrylic acid thus formed was esterified with beta-butylhexyl alcohol, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. At a concentration of .1%, the product gave a wetting speed of 30 seconds.

EXAMPLE '5 The salt of the decyl ester of sec.-butyl benzoyl sulpho propionic acid was prepared following Method B by first condensing sec.-butyl benzene with maleic anhydride. The sec.-butyl benzoyl acrylic acid thus formed was esterified with n-decyl alcohol, and the reuslting ester was reacted with sodium bisulphite to form the sulpho derivative. At a concentration of .05%, it gave a wetting speed of l8 seconds.

EXAMPLE '6 The salt of the n-decyl ester of hexylbenzoyl ,(l,3 dimethyl butylbenzoyl) sulpho propionic acid was prepared following Method B by first (1,3 dimethylbutylbenzene) with maleic anhydride. The hexylbenzoyl acrylic acid thus formed was esterified with n-decyl alcohol, and the resulting'ester was reacted with sodium bisulphite to form the sulpho derivative. At a concentration of .1%, the compound gave a wetting speed of 30 seconds.

EXAlVIPLE 7 The salt of the lauryl ester of toluoyl sulpho propionic acid was prepared following Method B. by firstcondensing toluene with maleicanhydride. The toluoyl acrylic acid thus formed was esterified with lauryl alcohol, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. At a concentration of .1%, it gave a wetting speed of 21 seconds and exhibited good detergency properties in soft water.

EXAMPLE 8 The salt of the lauryl ester of sec.-butyl benzoyl sulpho propionic acid was prepared following Method B by first condensing sec.-butyl benzene with maleic anhydride. The sec.-butyl benzoyl acrylic acid thus formed was esterified with lauryl alcohol, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. At a concentration of 2%, it gave a wetting speed of 27 seconds.

EXAMPLE 9 The salt of the myristyl ester of ethylbenzoyl sulpho propionic acid was prepared following Method B by first condensing ethylbenzene with maleic anhydride. The ethylbenzoyl acrylic acid thus formed was esterified with myristyl alcohol, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. At a concentration of 2%, the compound gave a wetting speed of 80 seconds, and was an effective sudsing agent andsoft water detergent.

EXAMPLE 10 The salt of the laurylester of chlorotoluoyl sulpho propionic acid was prepared following Method B by first condensing chlorotoluene with maleic anhydride. The chlorotoluoyl acrylic acid thus formed was esterified with lauryl alcohol, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. At a concentartion of ,1%, it gave a wetting speed of 120 seconds and exhibited good detergency properties in soft water.

EXAMPLE 11 EXAIVIPLE 12 The salt of the n-decyl ester of amyltoluoyl sulpho propionic acid was prepared following Method B by first condensing amyltoluene (prepared by alkylating toluene with pentene-l) with maleic anhydride. The amyltoluoyl acrylic acid thus formed was esterified with n-decyl alcohol, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. At a concentration of .l%, the compound gave a wetting speed of 25 seconds.

EXAMPLE 13 The salt of the myristyl ester of xyloyl sulpho propionic acid Was prepared following Method B by first condensing Xylene with maleic anhydride. The xyloyl acrylic acid thus formed was esterified with myristyl alcohol, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivatives. At a concentration of 2%, it gave a wetting speed of '76 seconds, and exhibited strong foaming properties.

EXAMPLE 14 The salt of the 2-ethyl octyl ester of xyloyl sulpho propionic acid was prepared following Method B by first condensing xylene with maleic anhydride. The xyloyl acrylic acid thus formed was esterified with 2-ethy1 octyl alcohol, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. At a concentration of .05% it gave a wetting speed of 30 seconds.

Of the foregoing compounds, the water soluble salts of the dodecyl esters of benzoyl sulpho propionic acid. and more specifically the sodium salt of the lauryl ester of benzoyl sulpho propionic acid; the water soluble salts of the dodecyl esters of chlorobenzoyl sulpho propionic acid, and more specifically the sodium salt of the lauryl ester of chlorobenzoyl sulpho propionic acid; and the water soluble salts of the dodecyl esters of toluoyl sulpho propionic acid, and more specifically the sodium salt of the lauryl ester of toluoyl sulpho propionic acid, are preferred.

Considerable modification is possible in the method of preparing the compounds as well as in selecting the various combinations of R1, R'1, R2 and M without departing from the scope of the present invention.

I claim:

1. As a surface active agent possessing marked detergent properties, the water soluble salts of the benzoyl sulpho propionic acid esters corresponding to the following formula:

where R1 is selected from the group consisting of hydrogen and alkyl groups containing from 1 to 6 carbon atoms; where R'1 is selected from the group consisting of hydrogen and a methyl group;

where A is selected from the group consisting of hydrogen and chlorine when R1 is as stated and R'1 is hydrogen, otherwise A is hydrogen; where B is an ethylene group; where R2 is an alkyl group containing from 10 to 16 carbon atoms;

where M is a cation providing Water solubility to the product; and where the total number of carbon atoms of R2 plus carbon atoms in substituted alkyl groups on the phenyl nucleus is at least 10 but not more than 16.

2. The product of claim 1 wherein M is sodium.

3. As a surface active agent possessing marked detergent properties, the water soluble salts of the benzoyl sulpho propionic acid esters corresponding to the following formula:

Y S 03M where Y is selected from the group consisting of hydrogen, chlorine and methyl; where R2 is an alkyl group containing from 10 to 14 carbon ator'ns; where B is an ethylene group, and where M is a cation providing water solubility to the product.

4. The product of claim 3 wherein R2 contains 12 carbon atoms, and wherein M is sodium.

5. As a surface active agent possessing marked detergent properties, a water soluble salt of a dodecyl ester of benzoyl sulpho propionic acid.

6. As a surface active agent, possessing marked detergent properties, the sodium salt of the lauryl ester of benzoyl sulpho propionic acid.

7. As a surface active agent, possessing marked 13 detergent properties, a'water soluble salt of a dodecyl ester of chlorbenzoyl sulpho propionic acid.

8. As a surface active agent, possessing marked detergent properties, the sodium salt of th lauryl ester of chlorbenzoyl sulpho propionic acid.

9. As a surface active agent possessing marked detergent properties, a water soluble salt of a dodecyl ester of toluoyl sulpho propionic acid.

10. As a surface active agent possessing marked detergent properties, the sodium salt of the lauryl ester of toluoyl sulpho propionic acid.

11. The method of preparing a surface active agent possessing marked detergent properties which comprises condensing, in a Friedel-Cra'fts acylation reaction, a phenyl derivative selected from the group consisting of benzene, monochlorobenzene, monoalkylbenzene, monoalkylmonochlorobenzene and monoalkyltoluene, said alkyl groups containing from 1 to 6 carbon atoms, 2o

12 with maleic anhydride to form the corresponding benzoyl acrylic acid, esterifying the resulting acid with a compound providing an alkyl ester group containing from 10 110 16 carbon atoms which provides, along with carbon atoms supplied by alkyl groups attached to the phenyl nucleus of said phenyl derivative, a total of from 10 to 16. carbon atoms, and reacting said ester with sodium bisulphite, at a temperature between about 80 C. and about 110 C., to form the sodium salt of a benzoyl sulpho propionic acid ester,

GLEN W. HEDRICK.

REFERENCES CITED The following references are of record in the file of this patent:

Bogert et al.: J. A. C. 3., vol. 47, pp. 526-535 (1925). 

1. AS A SURFACE ACTIVE AGENT POSSESSING MARKED DETERGENT PROPERTIES, THE WATER SOLUBLE SALTS THE BENZOYL SULPHO PROPIONIC ACID ESTERS CORRESPONDING TO THE FOLLOWING FORMULA: 